Fix panic in lexing of unterminated asm text literal at EOF

Author: zaneduffield

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Lexing of conditional directive expressions containing compiler directives, comments, or strings.
 - Lexing of compiler directives similar to conditional directives (e.g. `{$if_}`).
+- Lexing of unterminated asm text literals at EOF.
 
 ## [0.3.0] - 2024-05-29
 

core/src/defaults/lexer.rs

@@ -860,16 +860,20 @@ fn asm_text_literal(mut args: LexArgs) -> OffsetAndTokenType {
         match args.next_byte() {
             Some(b'\\') => {
                 args.offset += 1;
+                if args.next_byte().is_some() {
+                    args.offset += 1;
+                }
             }
             Some(b'\"') => {
                 return (args.offset + 1, TT::TextLiteral(TLK::Asm));
             }
             None | Some(b'\n' | b'\r') => {
                 break;
             }
-            _ => {}
+            _ => {
+                args.offset += 1;
+            }
         }
-        args.offset += 1;
     }
 
     warn_unterminated("asm text literal", args.input, start_offset);
@@ -2398,6 +2402,17 @@ mod tests {
         );
     }
 
+    #[test]
+    fn unterminated_asm_text_literal_at_eof() {
+        run_test(
+            r#"asm"\"#,
+            &[
+                ("asm", TT::Keyword(KK::Asm)),
+                ("\"\\", TT::TextLiteral(TLK::Unterminated)),
+            ],
+        );
+    }
+
     #[test]
     fn inline_assembly_with_comments() {
         run_test(